Doctor Whooves (The Doctor) has had a good and long run through time and space with Ditzy Doo. But it is that time again for him to regenerate bodies. But this time, it seems... different... What would happen if The Doctor regenerated... As a mare?

After an accident which results in the TARDIS damaged, Twilight Sparkle de-aged into a filly, and three curious stowaways, the Doctor finds himself caught in a web of intrigue spanning time and space that threatens to rend chaos upon the universe...

The Doctor finds himself stuck in prison, unable to remember anything he had experienced prior to his awakening. With the help of his diary, enchanted with magic, he tries to piece his life back together, not knowing what might await him at the end.

...If you mess with Nepeta Leijon's "meowrail", you're in for a treat. A colorful, bubbly, equestrian treat. A treat that may or may not be from My Little Hoofbeast: Friendship is Not an Emotion. (A Homestuck and MLP crossover.)

[Author's Note] Whup, this was going no where. I hardly even liked Doctor Who.Every Doctor Who and My Little Pony fan knows that Derpy would be a good companion, but why? Everyone has always thought that Derpy was, well, just ordinary Derpy. But nopony knows what Derpy has been through. She has been through a lot of predicaments and adventures with the Doctor, but this story brings us farther than that.This is my first legit story so tell me your opinion on it so I can know if I should fix some things.

*Note: This fanfiction is set in the time of the 11th Doctor and is during the time of the Ponds and the TARDIS interior before the Christmas SpecialThank you to dominiquelestrange a.k.a my sister for proofreading.